The present invention relates to adjusting mechanisms for alignment of automotive headlamps or the like, and more particularly relates to improved assembly and construction of such mechanisms.
Particularly successful modern adjusting mechanisms for alignment of vehicle headlamps are described for example in U.S. Pat. Nos. 4,674,018 and 4,893,219. In the described mechanisms an adjusting screw is coupled to the headlamp housing and extends into a gearbox or adjustment mechanism. The adjusting screw is operatively coupled to an adjusting drive shaft which is operated by conventional hand tools, by means of a pair of mitered gears and a threaded connection. The gear members can be assembled and sealed within the integral gear housing, while allowing the drive shaft and adjusting screw components to be assembled at a later time with a variety of shaft and screw lengths as required for different vehicle models.
Typically, multiple adjusting screws on adjustment mechanisms are employed for separate adjustment of vertical and horizontal alignment of the headlamp assembly, and each of the adjustment screws carries a coupling ball which is coupled into a socket to form a ball joint which transmits the axial translation of the adjusting screw to the headlamp assembly through a bracket which supports the socket and is fastened to the headlamp assembly. Conventionally, the socket support and securing bracket has been fabricated from metal for structural integrity and durability for headlamp adjustments through the life of the vehicle. The ball joint sockets, on the other hand, have been molded from a resilient plastic allowing the socket deformation to accept the snap-fit insertion of the coupling ball and retaining grip of the ball thereafter. However, press-fit mounting of the socket into a receiving hole in the bracket has led to a retention problem when the fit of the socket into the hole is too loose, or on the other hand when the hole/socket fit is too tight the socket can crack during the mounting insertion. In addition, the precision required to achieve a successful insertion of the socket into the bracket results in a time-consuming operation, particularly when multiple sockets and multiple brackets must be handled and assembled for each headlamp assembly. These and other disadvantages are eliminated in accordance with the present invention.